Wednesday, November 22, 2017

boot - Windows entry(UEFI) deleted, after installing ubuntu in legacy mode


I haven't found similar posts anywhere so I would be grateful for any help.


I've seen a couple of machines run Ubuntu using legacy mode and Windows using UEFI boot. This requires a switch of boot options in BIOS, which I'm OK with. So the behavior that I'm looking for is exactly this, in legacy mode, boot ubuntu, in UEFI mode, boot windows provided I make the BIOS switch at startup.


However, after a series of installations and running boot-repair, which i've explained below, I can only boot ubuntu in the legacy mode and when I switch to UEFI mode, I go to grub rescue because it says "no file found". Now I can't boot into windows in any mode!


This is the sequence that caused this.
-Windows 8 x64 preinstalled
-Tried installing ubuntu in uefi, ran boot repair and this seemed to delete everything.
-Reinstalled ubuntu in legacy mode, ran boot repair which doesn't work in the legacy mode


Now only ubuntu in legacy mode works. There is no grub menu at all in the uefi mode.


Here is the link to my boot info
http://paste.ubuntu.com/6608333/


How can I add a boot menu in the uefi mode while still having my ubuntu running in legacy mode.



Boot Repair has renamed the Windows boot loader file and put a copy of GRUB in its place. The Windows boot loader file should be EFI/Microsoft/Boot/bootmgfw.efi on the EFI System Partition (ESP), but Boot Repair has renamed it to bkpbootmgfw.efi and put GRUB in its place. You need to undo this damage. There's an option to do this on the Boot Repair Advanced menu page, or you can do it manually by renaming the file.


Incidentally, you may want to check out my rEFInd boot manager. It starts up in EFI mode and can pass control to the Windows EFI boot loader. It can also pass control to a BIOS-mode boot loader such as GRUB, although you'll need to uncomment the scanfor line in refind.conf and ensure that hdbios is among the options. rEFInd can also boot Linux in EFI mode. It's not clear why you want to do a BIOS-mode boot of Linux, but IMHO it's usually better to do an EFI-mode boot unless you've got some specific problem with that (like a video card that's not working well in EFI mode).


No comments:

Post a Comment

11.10 - Can't boot from USB after installing Ubuntu

I bought a Samsung series 5 notebook and a very strange thing happened: I installed Ubuntu 11.10 from a usb pen drive but when I restarted (...